New requirements and legislation regarding emissions in motor vehicles embody ever more stringent limit values for the particle emissions of internal combustion engines. Examples are LEV3 in the United States and EU6 in Europe which have recently been introduced. In turbocharged internal combustion engines, particularly gasoline engines with direct injection, a considerable fraction of the particles generated arises in that oil passes in an undesirable way into the combustion chambers and potentially directly into the exhaust gas.
In some example, one potential issue addressed is to reduce the particle emissions which are caused by oil. This is at least partially achieved by a system, comprising: an internal combustion engine having a turbocharger; an oil-lubricated bearing; a feed line for the oil; and a throughflow limiter for the oil. In other examples, a method for a turbocharged internal combustion engine is provided, comprising: during engine operating conditions, while oil is being fed to an oil bearing of a turbocharger; controlling throughflow and/or pressure of the oil via a throughflow limiter based on engine operating conditions, for example via an electronic controller.
Advantageous developments of the invention are defined in the dependent claims.
For example, it was found that oil escaping from the bearing of the turbocharger may contribute considerably to the particle emissions, specifically to an extent which may correspond to the EU6 limit values for particle emissions in the amount of 6*1011#/km in the NEDC (New European Driving Cycle).